Fork springs for light weight riders?

[IN_DET]

I've got a 95 GS500 and an 07 Ninja 650R and I've discovered what you've all known forever; the front of the GS sucks.

I know replacing the springs is the answer, but both I and my GF are light weights.  I'm 140lbs shes 120lbs.  I checked racetechs website and found that They recommend a .7 for her and a .73 for me.  The lowest they have is a .8 and I'm afraid this might be too much for me since thats a weight recommended for someone 180lbs.

The Progressives caught my interest because we're both so light weight and do mainly commuting on the bike, but those seem too have a range thats a bit low (for a progressive).  I believe it was .51-.82 or so.  The front springs on my 650R are progressive from the factory and while I'm not sure the starting point,  compressed they're 1.05.  The bikes are roughly the same weight give or take a pound or 2 according to the specs I've seen.  I'm happy with the front on the Ninja but it is a bit stiff going over sharp bumps so I usually raise off the bike a bit when I see them.

I really don't trust the front of the GS in stock form. It doesn't seem predictable, doesn't feel stable at speed, and compressive way too much under braking.  I'd been having some sputtering issues with it so I decided to go ring it out on a back road a bit.  I got it up to around 70 and proceeded to bring her down quickly so I could utilize very very wide section of road to pull a u-turn.  The nose compressed so much I lost the ability to continue my arc, went way wide, and stopped just inches from going off road.  At this point I determined that I didn't want my GF riding the bike as is daily because if she has to emergency stop, shes going down or into something.

[NiceGuysFinishLast]

I weigh about 135, not counting gear. I used .8 springs from Sonic and 5w oil. I'm extremely happy, especially when paired with my katana shock in the rear.

[scratch]

First off: www.peterverdonedesigns.com/introduction.htm

Second: I'm (still) ~125lbs and have gone back to the stock springs for my weight and riding in the rain (been riding 20 years).

Your assessment that it doesn't seem predictable may stem more from unfamiliarity with the bike.  Since the bike is undersprung for you, grabbing a handfull of brakes made you stand the bike up for the u-turn, instead of releasing the brakes for the u-turn.  With the forks fully compressed the bike would have a shorter wheelbase, which, with a decent lean angle, would most likely allow you to make the u-turn.  Grabbing the handfull of brakes also must have alarmed you so much that you reacted and stood the bike up.  If you know a bike has a lot of fork-dive, you can compensate by being smooth and gentle, at first, when applying the brakes.  Hope this helps.

Which way were you looking for the u-turn?

Edit: I'm beginning to suspect improper riding technique and will offer some tips, of course I should ask first, "How long have you been riding?"

When you applied the brakes and the front end dove, did you tighten up your grip on the bars and stiffen up [your upper body]?

If so, doing so didn't allow you to be able to steer, and so you were fighting your own body weight, and went wide instead of maintaining your lean angle and completing the turn.

When braking hard, pinch the tank with your knees, so you don't have to use your arms to keep you from sliding forward, then your arms will be free to steer.

A good way to check this is by flapping your elbows like a chicken; if you can't, you're too tight on the bars.

Hope this helps.

'88 GSXR750 springs are .75kg/mm and are available for ordering for about $50+.  Also, making sure you have fresh 10w fork oil will help, too (fork oil should be replaced every 2 years).

Otherwise, go for the Progressives, those I would suggest.

Going to 5w fork oil for the 650R might help allieviate the sharpness of the bumps by allowing the spring to compress faster.

[groff22]

NiceGuysFinishLast, Do you remember how much preload you cut from the spacers?

[galahs]

I personally think 0.8kg/mm would be fine and should come as stock.

[NiceGuysFinishLast]

NiceGuysFinishLast, Do you remember how much preload you cut from the spacers?

Not a clue, sorry..

[trumpetguy]

I'm REALLY happy with the progressives.  A big improvement from stock.  I'm about 180 lbs, and I'd like stiffer springs even than the progressives, so I think they'd work well for you.

[Chuck]

Buy my springs.  These guys are trying to lowball me! 

http://gstwins.com/gsboard/index.php?topic=37537.0